Core-unloading apparatus for an automatic core-making machine



Oct. 22, 1963 w. A. HUNTER 3,107,402

CORE-UNLOADING APPARATUS FOR AN AUTOMATIC CORE-MAKING MACHINE Filed June 2, 1961 5 Sheets-Sheet l INVENTOR. WILLIAM A.HUNTER.

Oct. 22, 1963 vy. A; HUNTER 3,107,402

CORE-UNLOADING APPARATUS FOR AN AUTOMATIC CORE-MAKING MACHINE Filed June 2, 1961 5 Sheets-Sheet 2 W IIII I lllllii U L. till 0 g 22 A'r'rv,

w. A. HUNTER 3,107,402

CORE-UNLOADING APPARATUS FOR AN AUTOMATIC CORE-MAKING MACHINE Oct. 22, 1963 5 Sheets-Sheet 5 Filed June 2, 1961 INVENTOR. WILUAM A.Hun1'aR w. A. HUNTER 3,107,402

CORE-UNLOADING APPARATUS FOR AN AUTOMATIC CORE-MAKING MACHINE Oct. 22, 1963 5 Sheets-Sheet 4 Filed June 2, 1961 INVEN TOR. WILLIAM A. Human:

W. A. HUNTER Oct. 22, 1963 CORE-UNLOADING APPARATUS FOR AN AUTOMATIC CORE-MAKING MACHINE 5 Sheets-Sheet 5 Filed June 2, 1961 INVENTOR. WCLLIAM A. Human United States Patent 3,107,402 CflRE-UNLQADHNG APPARATUS FOR AN AUTQMATIC CflRE-MAKENG MACHINE William A. Hunter, Morton Grove, 11]., assignor to Pettihone Mullilren Corporation, Chicago, 111., a corporation of Delaware Filed June 2, 1%1, Ser. No. 114,483 6 Claims. {CL 22-10) The present invention relates to an unloading apparatus for an automatic core-making machine and has particular reference to an apparatus which is adapted to be positioned adjacent to the core-making machine and, when properly adjusted for cooperation with the pattern drawn plate of such machine, will operate periodically or successively to lift the groups of finished cores from their released working position on the draw plate and transport them to a removed region where they are more conveniently accessible for further handling by an operator.

It is among the principal objects of the invention to provide an apparatus of this character having associated therewith a plurality of laterally spaced, longitudinally extending lifting fingers which are movable bodily as a unit in a closed rectangular path, first, from a lowered retracted position forwardly and horizontally to a lowered advanced position so that they will slide beneath the finished cores which are maintained in an elevated position above the pattern draw plate of the machine, then vertically upwardly to an elevated advanced position to raise the cores and cause them to clear the working parts of the machine, then rearwardly and horizontally to a retracted elevated position to carry the cores away from such working parts and, finally, vertically downwardly to the initial lowered retracted position to lower the cores to a convenient elevation where they are accessible to an operator for transportation thereof to a remote location for cooling and curing or other purposes.

It is a further object of the invention to provide such a core-unloading apparatus having associated therewith a movable carriage for supporting the core-lifting fingers, together with novel means for mounting the fingers thereon whereby the number of fingers employed may be varied at will as may also their lateral spacing or disposition on the carriage to accommodate a wide variety of core shapes and sizes, as well as variations in the number of cores to be unloaded during each cycle of the apparatus.

Another object of the invention is to provide a coreunloading apparatus of the type under consideration and wherein the finger-supporting carriage, during its forward and rearward movements, has a simple harmonic motion resulting in deceleration of the carriage as it approaches the end of its back and forth strokes. By such a phenomenon, particularly during the rearward stroke of the carriage to its elevated retracted position, the cores undergoing removal and transportation from the core-making machine are handled gently so that their positions on the lift fingers are not disturbed and so that the disposition thereof at the end of each removal operation will be precisely the same.

Still another object of the invention is to provide a coreunloading apparatus which is capable of adjustment so that it be applicable to, and useable with, core-making machines having different table elevations as well as different final draw plate positions, the necessary adjustments of the apparatus being made possible without requiring the use of tools and without requiring removal and replacement of machine parts.

A still further object of the invention is to provide such an apparatus having associated therewith a novel control system embodying pneumatic and hydraulic components which cooperate with one another in an effective and 3,107,492 Patented Oct. 22, 1963 novel manner to produce the desired carriage motions in their proper timed relationship.

The provision of a core-unloading apparatus which is relatively simple in its construction; one which is composed of a minimum number of moving parts and, therefore, is unlikely to get out of order; one which is rugged and durable and will, therefore, withstand rough usage; one which is smooth and silent, yet fast, in its operation, and one which otherwise is well-adapted to perform the services required of it; are further desirable features which have been borne in mind in the production and development of the present invention.

With these and other objects and advantages in View, which will become more readily apparent as the nature of the invention is better understood, the invention consists in the novel construction, combination and arrangement of parts shown in the accompanying five sheets of drawings forming a part of this specification.

In these drawings:

FIG. 1 is a side elevational view of a core-unloading apparatus constructed in accordance with the principles of the present invention, showing the apparatus operatively associated with an automatic core-making machine;

FIG. 2 is a top plan View of the core-unloading apparatus;

FIG. 3 is an enlarged sectional view taken substantially centrally, longitudinally and vertically through the coreunloading apparatus;

FIG. 4 is a still further enlarged sectional view taken substantially along the line 4-4 of FIG. 3;

FIG. 4a is a sectional view taken substantially along the line 4a4a of FIG. 4;

FIG. 5 is a rear end elevational view, partly in section, of the core-unloading apparatus;

FIG. 6 is a front end elevational view of the apparatus;

FIG. 7 is a sectional view similar to FIG. 3 but showing the parts in a different position or relationship; and

FIG. 8 is a diagrammatic view illustrating an exemplary control system, including electrical, pneumatic and hydraulic components, by means of which the apparatus may be operated.

General Considerations meral 10 and is shown as being positioned upon a foundry floor 11 or other supporting surface in operative relationship with an automatic core-making machine 12. The core-making machine 12 is exemplary of one form of machine with which the present unloading apparatus may be associated. It forms no part of the present invention and no claim is made herein to any novelty associated with the same, the novelty of the present invention consisting rather in the construction, combination and arrangement of parts of the unloading apparatus 10. For a full disclosure of the nature and operation of the coremaking machine 12, reference may be had to copending United States patent application Serial No. 138,195 filed on Sept. 14, 1961, and entitled Automatic Core Making Machine, now Patent No. 3,096,547, issued July 9, 1963.

Briefly, and for purposes of illustrating the function of the core unloading apparatus 10, it is pointed out that the core-making machine 12 involves in its general organization a hopper 14 which funnels sand into a magazine 16 when the latter is in a retracted or rearwardly shifted position. After the magazine 16 has been filled, it moves automatically forwardly and overlies an upper core box 18. At this time, a table 20 rises and lifts a lower core box 22 so as to force the same against the upper core box 18, after which the core box assembly (18, 22) is forced upwardly and bodily as a unit against the magazine 16. Air under pressure is then admitted or blown into the magazine 16 in order to force the sand therein into the subjacent core box cavity or cavities, depending, of course, upon the character of the core box assembly. The table 20 is then partially lowered in order to move the core box assembly downwardly and separate it from the magazine. This allows the magazine 16 again to be moved rearwardly to its retracted position for re-filling with sand during the succeeding machine cycle. Retraction of the magazine brings an upper gas burner arrangement 24 into operative register with the upper core box in order that the flames emanating therefrom maintain the necessary curing temperature for the sand contained therein, the sand being of the resin-bonded type. Heat is also applied to the lower core box by a lower burner arrangement (not shown) and, after a relatively brief period of curing time, the table 20 is further lowered so as to seat the upper core box 18 on a series of vertically extending pins 26 which project upwardly above the thus lowered lower core box 22. Continued downward movement of the table 20 serves to drop the lower core box from the upper core box and separate the two boxes, while at the same time, a stripper plate 28 engages a series of fixed vertically extending pins 30. The stripper plate 28 supports the pins 26 and thus, when the stripper plate has its motion arrested by the fixed pins 30, the pins 26 will remain stationary, and as the lower core box 22 continues to move downwardly under the influence of the descending table 29, the pins 26 will engage the underneath side of the core C, which has been formed in the closed and heated core box assembly, and hold the core in a supported position while the lower core box moves away from the core to effect the stripping operation. At the end of the machine cycle, the core C is left in an elevated position on the upper ends of the pins 26 where it is supported solely by its own gravitational weight. In its thus exposed position, the core is accessible for removal by the unloading apparatus 10 of the present invention. The operation of the machine 12 is repetitious and the unloading apparatus 10 is adapted to be operated either manually or automatically in timed relation with the machine cycle of the core-making machine 12.

Brief Description Still referrin to FIG. 1, and additionally to FIG. 2, briefly, the core-unloading apparatus 10 of the present invention involves in its general organization a housing 50 on which there is movably mounted a carriage assembly 52. The carriage assembly 52 is normally disposed adjacent to the rear end of the apparatus. It includes a plurality of adjustable lift fingers 54 which are movable bodily with the carriage and are adapted to be projected forwardly over the table 20 of the coremaking machine 12 in such a manner that they straddle or interlace with the pins 26 on which the core C rests, and underlie the core C. Thereafter, upon vertical movement of the carriage assembly 52, the fingers 54 move upwardly and engage the core C to lift the same from the upper ends of the pins 26. The carriage assembly 52, in the elevated position of the fingers 54, is then moved 'rearWardly to carry the core C away from the machine 12, and finally, the carriage assembly is lowered to its initial retracted position to bring the core C to a convenient elevation for handling in the removal thereof to a remote location. The carriage assembly 52 is adapted to move in a closed rectilinear path to accomplish the core-removing operations heretofore described, the path describing a true rectangle. The apparatus is cyclic in its operation and each linear movement of the carriage assembly may be regarded as consuming onequarter of a machine cycle. Only two positions of the carriage assembly 52 have been fully illustrated herein, namely, its position at the commencement of apparatus operations and its 180 position at the end of an apparatus half-cycle. Thus, in FIG. 3, the carriage assembly is shown as being in its rear or retracted lowered position, while in FIG. 6, the carriage is shown as being in its forward or advanced elevated position wherein the core C has been lifted from the pins 26 of the corcmaking machine 12 and rests upon the lift fingers 5 t. The forward lowered position of the carriage assembly 52 wherein the lift fingers 54 extend between and around the pins 26 has not been illustrated, nor has the rear elevated 270 position thereof been shown wherein the core is maintained elevated but remote from the machine table 20. These latter positions, however, have been indicated by fragmentary dotted line carriage outlines and will be apparent from the present description.

The core-unloading apparatus 10- is adapted to be positioned on the foundry floor or other supporting surface immediately in front of the core-making machine 12 in the working area of the machine and the machine is so designed, insofar as its height is concerned that the lift fingers 54 will, in the normal condition of the apparatus, assume an elevation wherein the general plane thereof lies slightly above the plane of the upper face of the lower core box 22, as shown in FIG. 1. The housing Si) is provided at its lower end with a flange 56 by means of which it may be bolted to the floor 11.

The Fixed Housing Referring now to FIGS. 3, 5 and 6, the housing 50 is generally of rectangular box-like design and has appreciable height and length, but comparatively small width. It provides an enclosure for a major portion of the operating mechanism of the apparatus and constitutes, in effect, a supporting framework for the movable carriage assembly 52 and certain operating instrumentalities which are disposed exteriorly of the enclosure. As shown in the drawings, the housing 56 is provided with a bottom Wall 60, a pair of closely spaced side walls 62 and 64, a forward end wall 65 and a rear end wall 68. The upper end of the housing Si) is open and is adapted to be normally closed by means of a. flat sheet metal cover plate 70. A partition wall 71 extends between the side walls 62 and 64 at a location adjacent to the rear end portion of the housing, and, in combination with the rear end wall 68, defines an oil reservoir 72, the purpose and function of which will be made clear presently. A limited top wall section 74 of the housing 50 extends over the oil reservoir 72 and closes the upper end thereof.

A partition wall 86) extends between the side walls 62 and 64 at a location adjacent to the front end of the housing and establishes an oil chamber 82. A limited top wall section 84 of the housing 50 is provided with a circular opening 86 therethrough, and seated within this opening 86 in sealed relationship is the flanged head portion 88 of a lift cylinder 90. The cylinder 99 is suspended from the rim of the opening 86, projects downwardly within the oil chamber 82 to a region near the bottom wall 60, and, in combination with the various side walls of the oil chamber 82, defines a relatively narrow annular space 91 which surrounds the lower regions of the cylinder 90 and forms a part of the chamber 82.

Slidably disposed within the cylinder 90 for vertical reciprocating therein is a plunger 92, the upper end of which carries a guide frame 94 for the previously mentioned carriage assembly 52. The specific nature of the guide frame 94 and its mode of attachment to the plunger 92 will be set forth in detail hereafter.

An oil bleeder port 95 is formed in the side Wall of the cylinder 94} near the bottom thereof and establishes communication between the oil chamber 82 and the annular space 91 within the cylinder 90. The front end wall 66 is formed with a port 96 in the upper region of the oil reservoir 72 and such port is connected by an air line 98 to a three-way air valve Val (see FIG. 8). The rear end wall 68 is similarly provided with a port 102 in its upper region thereof and this port is connected by an air line 194 to a second three-Way lair valve Va2. The porting and valve arrangement just described is only schematically illustrated in FIGS. 3 and 7, and it has further been schematically shown in FIG. 8. Its function will be made clear presently.

The housing 56 is formed with certain structural adjuncts such as a flanged rim 1%, internal reinforcing ribs 11%, an inside supporting flange 112, an outside crescent or horseshoe-shaped guide and stop flange 114, and other details which will be mentioned subsequently if functionally significant.

The Lift Carriage Guide Frame The carriage assembly 52 is horizontally reciprocable on the previously mentioned guide frame 94 and the latter is vertically reciprocable bet-ween raised and lowered positions under the influence of the plunger 92. The guide frame 94 is in the form of an elongated, inverted, U- shaped, trough-like member 120 having a top wall 122 and depending side walls 124. The side walls 124 carry on the inner side portions thereof horizontally extending guide rails 126 which are designed for cooperation with respective roller-carrying, carriage-supporting plates 125 on the carriage assembly 52,, as will be described subsequently. The forward end region of the inverted, U- shaped member 12d carries a reinforcing plate 130 which seats upon the upper end of the plunger 92, suitable screws 132 being provided to fasten the inverted, U- shaped, trough-like member 129 and the plate 13%) to the plunger 92.

From the above description, it will be seen that upon movement of the plunger 92 between its fully retracted or lowered position and its fully extended or raised position, the lift carriage guide frame 94 will likewise be moved between lowered and raised positions, thus carrying with it the horizontally shiftable carriage assembly 52 which is capable of effecting its horizontal shifting movements in either the raised or the lowered position of the guide frame 94. i

In order that the lift fingers 54 may, during normal apparatus operations, be projected beneath the elevated core C at the proper elevation above the table 20 of the core-making machine (see FIG. 1) and otherwise either selectively brought into proper registry with cores of varying shapes and sizes and with cores which are maintained at different heights above the table, or projected beneath different portions of any given core for lift purposes, means are provided for varying the range of displacement of the guide frame 94, as well as for varying the amplitude of displacement of the guide frame.

Accordingly, the outside crescent-shaped flange 114 (see FIG. 3) at the upper rim of the housing 50' and near the forward end of the apparatus defines a vertically disposed opening 133 therein. An upwardly extending, threaded, anti-torque guide rod 13 has its upper end secured by a fastening screw 135 to the reinforcing plate 13% and nested Within a reinforcing sleeve 136 which is welded to the plate 130. The rod 13? projects downwardly through the opening 133 and is slidable therein during the vertical movements of the guide frame 94.

The guide rod 134 is formed with flattened sides 137 which interrupt the threaded portions of the rod. Two wear shoes 13% (see FIG. 6) are interposed between the crescentshaped flange and the fiat sides 137 of the rod 134 and serve to confine the rod therebetween and also to prevent lateral movement of the rod in either direction.

Means are provided for varying the amplitude of vertical displacement of the guide frame 94, as well as for varying its range of vertical movement so that cores C at varying heights above the table 20 of the core-making machine 12 may be accommodated. Accordingly, the threaded rod 134 receives thereon upper and lower stop nuts 139 and 13%, these nuts being vertically adjustable along the rod by turning thereof in one direction or the other. The two stop nuts are engageable with the crescent-shaped flange 114, the upper stop nut 139 controlling the lowermost position of the guide frame 94-, and the lower stop nut 139a controlling the uppermost position of said frame.

The Carriage Assembly The lift carriage assembly 52 involves in its general organization two elongated, vertically extending, side plates 140' which are connected together and maintained in spaced relationship by means of a transverse tubular member 142, the carriage assembly thus being generally of H-shape configuration, as viewed in FIGS. 5 and 6. Each side plate 140' has secured thereto on the outside face thereof a pair of vertically extending guide rails 144 which define therebet-ween a guide channel 1%. The two guide channels 146 are designed for cooperation with a pair of drive rollers 143 in a manner that will presently be set forth.

The previously-mentioned carriage-supporting plates 123 are welded as at 150 to the transverse tubular member 142, the plates being notched in semi-circular fashion to provide appreciable coextensive welding areas on the parts to be welded. The carriagesupporting plates 128 are longitudinally elongated and each plate carries at widely separated regions therealong two pairs of rollers 152, the rollers of each pair straddling the adjacent guide rail 126 and being adapted to travel therealong. The carriage assembly 52 as a whole is thus tractionally supported on the two guide rails for longitudinal reciprocation therealong.

As best shown in FIGS. 3 and 7, a transverse fingersupporting bar 154- is bolted as at 156 to the side plates 140 and bridges the distance thereacross. It extends laterally outwardly, an appreciable distance on opposite sides of the apparatus, as shown in FIGS. 5 and 6. The forward face of the bar 154 is formed with an elongated T-slot 158 therein and the previously-mentioned lift fingers 54 are adjustably secured to the bar 154 for individual lateral adjustment therealon-g by means of T-head clamping bolts 160 which pass through blocks 162,. The latter are welded as at 164 to the underneath sides of the fingers 54 at a location adjacent to the extreme rear ends of the fingers. The blocks 1-62 and the T-head bolts 160 constitute the sole supporting means for the lift fingers 54 on the carriage assembly 52.

The carriage assembly 52 is movable in opposite directions on the guide rails 126 between the retracted rear position wherein it is shown in FIG. 3 and the forward advanced position wherein it is shown in FIG. 7, movement of the carriage assembly being possible in any position of elevation of the guide frame 94, although normally in the cyclic operation of the apparatus movement of the carriage assembly in :one direction or the other is effected only when the guide frame 94 is in either of its extreme positions. Specifically, the carriage assembly will move forwardly only when the guide frame 94 is lowered and it will move rearwardly only when the lift frame is elevated.

The Carriage Reciprocating Mechanism Referring now to FIGS. 3, 4 and 7, the transverse partition walls 71 and St in combination with the side walls 62 and 64 of the housing 59, establish a central operating chamber Within which there is disposed the operating mechanism for effecting reciprocation of the carriage assembly 52. This operating mechanism incudes a rock shaft 172 which extends across the chamber 170 and between the housing side walls 62 and 64 at a location near the bottom of the chamber and, as shown in FIGS. 5 and 6, is rotatably j'ournalled in bearing plates 174 which are supported in thickened bosses 176 on the housing side walls. The ends of the rock shaft 172 are reduced as at 178. They project outwardly on opposite sides of the housing 50 and have fastened thereto the lower ends of respective rocker arms 130. The rocker arms 180 extend in substantially parallelism upwardly along the housing side walls 62 and 64, and the extreme upper ends of these rocker arms carry the aforementioned drive rollers 148 which ride in the vertically extending guide channels 146. The guide channels 146 and drive rollers 148 establish in effect heavy duty pin and slot connections between the rocker arm 180 and the carriage assembly 52 whereby the oscillatory movement of the rocker arms is translated into linear straight-line motion of the carriage.

Within the operating chamber 170, the rock shaft 174 has keyed thereto a rocker fork 182, the fork being centered on the shaft midway between the housing side walls 62 and 64. The rocker fork 182 constitutes, in effect, a crank arm which extends radially of the shaft 172. The outer end region of the fork is bifurcated to provide a pair of opposed spaced bearing surfaces 184. A drive member in the form of a unitary casting 186 of generally U-shaped cross section, as viewed in FIG. 40, includes a pair of side portions 188, such side portions being connected together by a transverse bight portion 190. A shaft 192 extends across the side portions 188 and is secured in place by a pin 194. A roller 196 on the pin 192 between the side portions 188 rides in the bifurcation in the rocker fork 182 and is designed for cooperation with the bearing surfaces 184. The roller 196 and the bearing surfaces 184 established by the bifurcation in the rocker fork 182 establish in effect a heavy duty pin and slot connection between the rocker fork and the casting 186 whereby uniform oscillatory movement of the casting is translated into simple harmonic oscillatory movement of the rocker fork. The side portions 188 of the casting 186 are formed with a pair of aligned openings 198 therethrough and the casting as a whole is pivotally mounted within the chamber 170 on a pair of flanged stub shafts 200. The latter project through thickened bosses 202 on the housing side walls 62 and 64 and are secured in position by fastening screws 204. The stub shafts 200 have reduced inner ends 206 which extend into roller bearings 208 in the openings 198 in the side portions 188 of the casting 186.

The casting 186, when considered as a whole, const itutes, in effect, a bell crank lever, the pivotal axis of which is the common axis of the stub shafts 2th). The roller 196 is carried at one end of the bell crank lever and the other end of the lever carries a cross pin 210 which extends across the casting side portions 188 and is anchored by a set pin 212. The cross pin 210 is pivotally connected to the outer end of a piston rod 214 which is associated with a floating or pivoted cylinder 216. One end of the cylinder 216 is pivoted as at 218 (see FIG. 3) to a web 220 which extends between the inside supporting flange 112 and the forward end wall 66.

The piston rod 214 carries a piston 222 which is reciprocable within the cylinder 216, and the cylinder is provided with fluid ports 224 and 226 at the end regions thereof. The cylinder 216 is an oil cylinder and the fluid ports 224 and 226 are adapted to be supplied with oil under pressure in order selectively to move the piston 222 in opposite directions.

From the foregoing description, it will be seen that when oil under pressure is admitted to the upper end of the cylinder 216 through the port 224, as viewed in FIG. 3, the piston 222 and the rod 214 will be driven or forced downwardly with the result that the rod will be forced outwardly of the cylinder and apply torque or tilting movement to the casting 186 through the medium of the cross pin 210 thereby causing the casting to rock in a counterclockwise direction about the axis of the stub shafts 208. Such rocking movement of the casting 186 will carry the roller 196 to the right, as seen in FIG. 3, and causes the casting to describe an are which will bring the roller into driving engagement with one of the bearing surfaces 134 so as to shift the rocker fork 182 in a clockwise direction about the axis of the shaft 172 on which the fork is mounted and to which it is keyed.

Rocking movement of the rocker fork 132 in this manner will effect rocking movement of the shaft 172 and of the two rocker arms 188 on the outside of the housing 50. As viewed in FIG. 3, these rocker arms 180 will swing in a clockwise direction, thus causing the rollers 148 at the upper ends thereof to ride upwardly in the guide channels 146 afforded by the guide rails 144, while at the same time, the entire carriage assembly 52 will slide to the right along the supporting guide rails 126. At such time as the piston rod 214 becomes fully extended, the carriage assembly 52 will have moved forwardly along the guide rails 126 and come to rest at a region adjacent to the forward end of the housing 50, such position of the carriage being indicated by the fragmentary dotted line indication of the carriage side plates 140 in FIG. 3 at the upper right-hand corner of this view. It should be borne in mind that in both the full-line and the dottedline positions of the carriage assembly, the carriage guide frame 94 is in its lowered position. The full-line position of the carriage assembly represents the initial starting position of the apparatus at 0 in the apparatus cycle, while the dotted-line position represents the position of the carriage assembly in the cycle.

Return of the carriage assembly from its dotted-line position to its full-line position, as viewed in FIG. 3, is not effected with the guide frame lowered. Such return is only effected by movement of the carriage through its full rectilinear path of movement wherein the guide frame 94 is raised under the influence of the plunger 92, as shown in FIG. 7, to carry the forwardly positioned carriage assembly upwardly with the guide frame. Then, after such raising of the guide frame, oil may be admitted to the lower end of the cylinder 216 through the port 226 to retract the piston rod 214 and rock the casting 186 in a reverse or clockwise direction and restore the rocker fork 182 to its initial left-hand position, as viewed in FIGS. 3 and 7, but with the carriage assembly raised, as shown in full lines in FIG. 7.

The Pneumatic and Hydraulic Connections for the Carriage Assembly Driving Mechanism As best seen in FIG. 3, the oil cylinder 90 is provided in its lower portion with an oil chamber 250 which communicates through the port with the oil chamber 32. The upper end of the cylinder 90 is provided with a conventional oil seal 252 in the form of a packing gland. The partition Wall 80 is formed with a port 254 which is connected by an oil line 256 to an oil shut-off valve V0, while a second oil line 258 connects the oil shut-off valve V0 to the port 226 in the lower region of the floating cylinder 216. An oil line 260 extends between the port 224 in the upper region of the cylinder 216 and the upper end of a standpipe 262 which has its upper end projecting above the top wall section 74 of the housing 50 and sealed thereto as at 264. The lower end of the standpipe 62 projects below the level of oil which is maintained in the oil reservoir 74. A splash plate 266 is mounted on the standpipe 262 and a web 268 serves to isolate the oil section of the reservoir from the air section 270 which exists above the web.

The air valves Val and Va2, which are connected to the air reservoirs 72 and 82, respectively, are of the three- Way type and may be of any suitable conventional construction. Where the apparatus is to be designed as a fully automatic one, the operation of which is correlated with the operation of the core-making machine 12 with which the apparatus is associated, the valves Val and Va2 will be of the solenoid-actuated type and suitable electric control circuits may be provided for operating these valves. Such control circuits may involve suitable relay mechanisms with holding circuits for effecting proper operation of the valves at various points in the apparatus cycle or circuits, which depend for their energization upon the use of conventional stepping switches, may be employed. In either event, circuit control may be effected, at least in part, by the appropriate positioning of limit switches on the housing 50 so that they will be actuated by moving parts or elements, preferably at the end of each quarter-cycle of apparatus operation. Exemplary of such electrical controls are a series of four limit switches including a pair of switches S1 and S2 (see FIGS. 3 and 7, respectively) which are positioned on the side wall 62 of the housing in the path of movement of the rocker arms 180, and a second pair of switches S3 and S4 which are disposed onthe forward end wall 66' in the path of movement of the adjustable stop nuts 139 and 139a, respectively. The oil valve V may likewise be of the solenoid-actuated type.

The air valves Val and Va2 have been illustrated in FIG. 3 as block diagrams, but in FIG. 8, the operation of these valves has been schematically shown. The two valves are identical and each includes a valve casing 272 having communication ports 274 :and 276 therein and a bleeder port 27 8. Each valve includes a rotatable core 289 having a passage 282 therein, adapted in the full-line open position of the valve to establish communication between the ports 274 and 276 and adapted in the dotted line or closed position of the valve to connect the ports 276 and 278 to bleed the valve to the atmosphere.

The oil valve V0 includes a casing 284 having ports 286 and 28S therein, and a rotatable core 2.90 having a passage 292 therethrough. In the full-line or open position of the core 290, the passage 292 establishes communication between the ports 286 and 288 so that oil may flow through the valve, while in the dotted-line position of the core 290, the ports 286 and 288 will be out of communication with each other and the flow of oil through the valve is prevented.

The electric circuitry for the various limit switches S1, S2, S3 and 84 has not been illustrated herein since such circuitry may vary widely. For a full understanding of the operation of the present core-unloading apparatus, it is necessary merely to point out the sequence of operation of the valves Val, V012 and V0 with relation to the apparatus cycle. The general function of the four switches will, however, be briefly outlined without reference to the electrical circuits which they may control, after the necessary sequence of valve operation has been set forth in connection with the following description of the operation of the apparatus.

Operation of the Apparatus In the operation of the core-unloading apparatus with the sarne operatively positioned in front of the core-making machine 12, as shown in FIG. 1, with the carriage 52 in its retracted lowered position and with the valves Val and Va2 closed and the valve V0 open, the air valve Va2 (see FIG. 8) is opened so as to establish communication through the passage 282 between the line 104 and an air supply line 294 leading from a source S of air under super-atmospheric pressure. Air is thus admitted through the port 102 in the rear end wall 68 of the casing 50 to the oil reservoir 72, thus raising the interanl pressure within the reservoir and forcing oil upwardly through the standpipe 262 and the oil line 260 and causing the same to enter the upper end of the cylinder 216 (see also FIG. 3) through the port 224 therein. Admission of fluid through the port 224 drives the piston 222 and the piston rod 214 downwardly in the cylinder 216 so as to project the rod and rock the pivoted casting 186 in a counterclockwise direction to, in turn, move the rocker fork 182 in a clockwise direction, as previously described, thereby turning the rock shaft 172 and swinging the rocker arm's 180 in unison in a clockwise direction, as viewed in FIG. 3. It is to be noted at this point that projection of the piston rod 214 from the cylinder 216 and retraction of the rod into the cylinder induces uniform rocking movement of the pivoted casting 186. By reason of the pin and slot connection afforded, in effect, by the roller 1% and the bearing surfaces 184- established by the bifurcation in the rocker fork 182, this uniform rocking movement of the casting 186 is translated into oscillatory motion of the rocker fork with an element of simple harmonic motion being imparted to the rocker fork whereby it moves across the mid-point of its stroke at a rate which is faster than its movement elsewhere in its stroke. Such simple harmonic movement of the rocker arms causes the rollers 148 at the upper ends thereof to ride upwardly in the guide channels 144 and cause the carriage assembly 52 to shift to the right, as viewed in FIGS. 3 and 8. At 45 in the apparatus cycle, the rocker arms 180 and the carriage assembly 52 reach their mid-position with the rollers 148 at the top of their stroke and, thereafter, continued movement of the rocker arms in a clockwise direction will cause the rollers to descend while the carriage continues its mot-ion to the right. It will be observed, therefore, that the previously described simple harmonic oscillatory motion which is imparted to the rocker fork 182 is compounded with a second simple harmonic motion which is afforded the carriage 52 by reason of the pin and slot connection established by the guide rails 144 and rollers 148. This results in a marked deceleration in the motion of the carriage 52 near the ends of its forward and rear-ward strokes since the two elements of simple harmonic motion are so compounded in assisting series relationship, as distinguished from bucking series relationship, that they amplify the deceleration effect on the carriage as it approaches the end of its stroke in .either direction.

During such projection of the piston rod 214 and movement of the carriage assembly 52, the oil which is expelled from the lower regions of the cylinder 216 will pass through the line 258, the valve V0 and the line 256, and enter the oil chamber 82, thus raising the level of oil therein slightly but not affecting the plunger 92 inasmuch as the valve Val is in its closed condition so that no air may be admitted to the oil chamber 82 but so that air may be bled from the upper regions of the chamber to the atmosphere through the port 96, the line 93, and the valve bleeder port 27 8.

When the rocker arms 180 and the carriage assembly 52 reach the limit of their forward stroke as indicated by the fragmentary dotted line disclosure thereof in FIG. 3, the oil valve V0 will be closed, while the air valve Val will be opened to admit air from the source S, through line 296, the valve Val, the line 98, and the port 96 to the interior of the oil chamber 250 above the oil level thereof. With the valve V0 closed, pressure will be built up in the oil chamber 82 and this pressure will be communicated through the port 95 to the interior of the cylinder, i.e., the oil chamber 250. The plunger 92 will thus be forced upwardly within the cylinder 90, thus elevating the carriage guide frame 94. Upward movement of the plunger 92 and the guide frame 94 will continue until such time as the stop nut 139a engages the crescenoshaped flange 114 and prevents further upward travel of these parts.

At such time as the carriage assembly 52 initially reaches the limit of its forward movement at in the apparatus cycle and with the guide frame 94 in its lowered position, the core-lifting fingers 54- on the carriage assembly 52 will be projected beneath the elevated core C on the core-supporting pins 26 (see PEG. 1). As the carriage assembly and the guide frame rise bodily as a unit under the influence of the plunger 92, as heretofore described, the horizontally disposed fingers 54 will engage the underneath side of the core C, or will engage a downwardly-facing flange or other surfaceof the core, and cause the core to be elevated from the pins 26, as shown in FIG. 7.

The guide frame 94 and the carriage assembly 52 ar-' rive at their upper positions at a point, which, for purposes of description, may be regarded as 180 in the apparatus cycle. At this time, the valve Val is allowed to remain open, while the oil valve V will again be opened and the air which is forced into the air chamber 82 under pressure will maintain the plunger 92 extended to maintain the guide frame 94 elevated, while at the same time, oil will pass outwardly from the chamber 32 through the port 254 and flow through the line 256, the valve V0, the line 253, and enter the lower end of the cylinder 216 through the port 226, thus driving or sliding the piston 222 upwardly and retracting the plunger 214 and causing the pivoted casting @186 to swing in a clockwise direction to retract the carriage assembly 52 toward its rearniost position by a reversal of the movements of the various moving parts from those previously described.

During the upward movement of the piston 222 and the rod 214 in the cylinder 216, the oil in the upper region of the cylinder will be expelled from the cylinder through the port 224, the line 260, the standpipe 252, thus returning this oil to the reservoir 72. Air in the upper region 270 of the reservoir 72 may escape to atmosphere through the port 162, the line 104 and the air valve Va2.

It is to be noted at this point that although the guide frame 94 is in its elevated position during such return movement of the carriage assembly 52, the longitudinal extent of the guide channels 144 on the side plates 149 of the carriage assembly is such that at no time will the rollers 148 leave the channels provided for them. In the lowered position of the guide frame and during forward travel of the carriage assembly, the rollers 148 operate in the lower region of the channels 144 between vertical limits roughly represented by the dotted lines aa and bb. In the raised position of the guide frame and during rearward travel of the carriage assembly, these rollers operate in the upper region of the channels 144 between vertical limits roughly represented by the dotted lines bb and c--c. It will be understood, of course, that the positions of these limits will vary with the adjustments of the stop nuts 139 and 139a which control the range of movement of the carriage assembly and the lifting fingers supported thereby.

Upon return of the carriage assembly 52 to its fully retracted position at the rear end of the raised guide frame 94 at 270 in the apparatus cycle, the air valve Val will be closed t shut off the supply of air to the air chamber 82 and the valve V0 will be closed. The oil which previously entered the chamber 250 in the cylinder 90 to drive the plunger 92 upwardly and raise the guide frame 94 will now be forced out of the cylinder through the oil bleeder port 95 to raise the level of oil in the surrounding oil chamber 82, such ejection of oil from the chmber 250 taking place under the influence of the gravitational weight of the carriage and lift frame.

With the various valves Val, Va2 and V0 operated at the proper times in the apparatus cycle indicated above, it is obvious that the limit switches S1, S2, S3 and S4 will be associated with suitable electrical circuitry which will operate selectively to energize and deener-gize the solenoids (not shown) associated with these valves at the termination of each carriage assembly movement or guide frame movement. An initial impulse may be received from the core-making machine 12 to initiate the apparatus cycle of the core-unloading apparatus 10, at which time the rocker arm 186' will be in operative engagement with the limit switch S1, which will serve to open the valves Va2 and V0. When the rocker arm 180 assumes the dotted-line position wherein it is shown in FIG. 3, the limit switch S2 will be engaged thereby and this will actuate electrical instrumentalities for closing the valve V0 and opening the valve Val. Upon raising of the guide frame 94, when the stop nut 139a engages the limit switch 33, control instrumentalities are made effective to open the valve V0 and the valve V2. As the rocker arm 186 is returned to its initial position, the switch S1 is again operated to open the oil valve V0 and to close the air valve Val. Finally, upon dcscent of the guide frame 94, the stop nut 139 engages the limit switch S4 and control instrumentalities are made effective to open the valves V412 and V0 to commence the next cycle of apparatus operation, subject, of course, to an initial starting impulse from the core-making machine 12.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification, as various changes in the details of construction may be resorted to without departing from the spirit and scope of the invention. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a core-unloading apparatus adapted to be positioned adjacent to a coremaking machine and successively to remove finished cores from the discharge area of the machine, in combination, a framework, a lift cylinder on said framework and having its axis extending vertically, a plunger slidable in said lift cylinder, a guide frame fixed to the upper end of said plunger and movable bodily with the plunger between raised and lowered positions above the housing corresponding to the raised and lowered positions of the plunger respectively, a carriage mounted on the guide frame for horizontal movement between retracted and advanced positions respectively, a plurality of horizontally disposed core-engaging lift fingers on said carriage, said fingers being adapted when the guide frame is in its lowered position and the carriage is in its advanced position on the guide frame to underlie a core positioned in the discharge area, a horizontal rock shaft on said framework, a rocker arm fixedly secured to the rock shaft, means on said carriage defining a vertically extending guide channel, a roller carried on the distal end of said rocker arm and slidable in said guide channel, an operating cylinder pivoted to the framework, a piston rod slidable in said operating cylinder, a bell crank lever mounted on the framework for swinging movement about a horizontal axis and having one arm cooperatively connected to the piston rod, and a rocker fork fixedly secured to the rock shaft and have a bifurcated outer end, said bell crank lever having its other arm engageable between the furca tions of said rocker fork.

2. A core-unloading apparatus as set forth in claim 1 and including, additionally, adjustable interengaging limit stop means on the guide frame and housing respectively for limiting the extent of upward movement of the plunger in said lift cylinder.

3. In a core-unloading apparatus adapted to be positioned adjacent to a core-making machine for removing successively finished cores from the discharge area of the machine, in combination, a stationary framework, a guide frame mounted for vertical movements in opposite directions on said framework between an elevated and a lowered position, a carriage mounted on said guide frame for movement bodily therewith and for independent horizontal movements in opposite directions between an advanced and a retracted position, a plurality of core-engaging iift fingers on said carriage, reversible means for moving said guide frame between its elevated and lowered positions, and reversible means for moving said carriage between its advanced and its retracted positions, said carriage-moving means comprising a rocker arm pivoted at one end thereof to said framework, means establishing a pin and slot connection between the other end of the rocker arm and said carriage, a drive member mounted on said framework for rocking movement about an axis, an eccentric pin on said drive member, means including said eccentric pin establishing a pin and slot connection between said drive member and said [rocker arm in a medial region of the latter, and means for eifect ing rocking movements of said drive member in opposite directions.

4. A core-unloading apparatus as set forth in claim 3 and wherein said means for effecting rocking movements of said drive member comprises a second eccentric pin on said drive member, and a fluid cylinder and plunger assembly interposed between said second eccentric pin and a fixed point on said framework.

5. A core-unloading apparatus as set forth in claim 3 and wherein said means for moving the guide frame comprises a fluid cylinder and plunger assembly interposed between the guide frame and the framework, and said means for effecting rocking movements of said drive member comprises a second eccentric pin on said drive member, and a fluid cylinder and plunger assembly interposed between said second eccentric pin and a fixed point on said framework.

6. A core-unloading apparatus adapted to be positioned in front of a core-making machine and to remove successively finished .cores from the working area of the machine, said apparatus comprising: a stationary framework, a guide frame movable vertically on said framework between elevated and lowered positions, a carriage on said guide frame movable bodily therewith and also movable independently and horizontally between advanced and retracted positions on the guide frame, said carriage being movable on the lowered guide frame from its retracted positionto its advanced position so as to underlie a core in the discharge area of the coremaking machine, and being movable on the elevated guide frame from its advanced position to its retracted position to transport the core from said discharge area, means for moving the guide frame between its elevated and its lowered positions, and means operable supported on the firamework and operable in either position of the guide frame by a pin and slot connection to move said carriage between its advanced and its retracted positions on the guide frame with a compound harmonic motion wherein the carriage gradually decreases its speed as it approaches either position and increases its speed as it approaches its mid-position.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A CORE-UNLOADING APPARATUS ADAPTED TO BE POSITIONED ADJACENT TO A CORE-MAKING MACHINE AND SUCCESSIVELY TO REMOVE FINISHED CORES FROM THE DISCHARGE AREA OF THE MACHINE, IN COMBINATION, A FRAMEWORK, A LIFT CYLINDER ON SAID FRAMEWORK AND HAVING ITS AXIS EXTENDING VERTICALLY, A PLUNGER SLIDABLE IN SAID LIFT CYLINDER, A GUIDE FRAME FIXED TO THE UPPER END OF SAID PLUNGER AND MOVABLE BODILY WITH THE PLUNGER BETWEEN RAISED AND LOWERED POSITIONS ABOVE THE HOUSING CORRESPONDING TO THE RAISED AND LOWERED POSITIONS OF THE PLUNGER RESPECTIVELY A CARRIAGE MOUNTED ON THE GUIDE FRAME FOR HORIZONTAL MOVEMENT BETWEEN RETRACTED AND ADVANCED POSITIONS RESPECTIVELY, A PLURALITY OF HORIZONTALLY DISPOSED CORE-ENGAGING LIFT FINGERS ON SAID CARRIAGE, SAID FINGERS BEING ADAPTED WHEN THE GUIDE FRAME IS IN ITS LOWERED POSITION AND THE CARRIAGE IS IN ITS ADVANCED POSITION ON THE GUIDE FRAME TO UNDERLIE A CORE POSITIONED IN THE DISCHARGE AREA, A HORIZONTAL ROCK SHAFT ON SAID FRAMEWORK, A ROCKER ARM FIXEDLY SECURED TO THE ROCK SHAFT, MEANS ON SAID CARRIAGE DEFINING A VERTICALLY EXTENDING GUIDE CHANNEL, A ROLLER CARRIED ON THE DISTAL END OF SAID ROCKER ARM AND SLIDABLE IN SAID GUIDE CHANNEL, AN OPERATING CYLINDER PIVOTED TO THE FRAMEWORK, A PISTON ROD SLIDABLE IN SAID OPERATING CYLINDER, A BELL CRANK LEVER MOUNTED ON THE FRAMEWORK FOR SWINGING MOVEMENT ABOUT A HORIZONTAL AXIS AND HAVING ONE ARM COOPERATIVELY ACONNECTED TO THE PISTON ROD, AND A ROCKER FORK FIXEDLY SECURED TO THE ROCK SHAFT AND HAVE A BIFURCATED OUTER END, SAID BELL CRANK LEVER HAVING ITS OTHER ARM ENGAGEABLE BETWEEN THE FURCATIONS OF SAID ROCKER FORK. 